Submersible double-acting fluid piston deep well pump



Nov. 30, 1948. B. F. SCHMIDT 2,455,022

SUBMERSIBLE DOUBLE-ACTING FLUID PISTON DEEP WELL PUMP Filed Aug. 8, 194415 Sheets-Sheet 1 FLOW TUBING N ELECTRIC` CABLE L ma? CONNECTQR lCOUPLINCI ma. Moron IloUsING If 4 Mama HOUSING PRESSURE EQUALIzEIzJuNcrIoN Box ELECTRIC MOTORS 1"1 LzLL MOTOR-PUMP SEAL PRESSURE EQUIUZERNov. 30, 1948. B. F. SCHMIDT 2,455,022

SUBMERSIBLE DOUBLE-ACTING FLUID PISTON DEEP WELL PUMP 13 Sheets-Sheet 2Filed Aug. 8, 1944 Nov. 30, 948. B, F, sCHMlDT 2,455,922

SUBMERSIBLE vDoUL'rl-ACTIMI FLUID PISTON DEEP WELL PUMP Filed Aug. 8,1944 13 Sheets-Sheet 5 47V l X45 Nov, 30, ma

B. F. SCHMIDT 2,455,022 SUBMERSIBLE DOUBLE-ACTING FLUID PISTON DEEP WELLPUMP Filed Aug. 8, 1944 15 Sheets-Sheet 5 Snvcntor Sch/Mm NOV- 30, 1948-B. F. SCHMIDT SUBMERSIBLE DOUBLE -ACTING FLUID PISTON DEEP WELL PUMP 13Shee'bs--Sheel'I 6 Filed Aug. 8, 1944 Nov. 30, 1948. B. F. SCHMIDT2,455,922

SUBMERSIBLE DOUBLE-ACTING FLUID PISTON DEEP WELL PUMP Filed Aug. 8, 194413 Sheets-Sheet 7 Nov. 30, 1948. B. F. SCHMIDT SUBMERSIBLE DOUBLE-ACTINGFLUID PISTON DEEP WELL PUMP :inventor M107,

13 SheebS-Sheeb 8 /SCH Filed Aug. 8, 1944 ntor w w m g., .m l O /I 5 a5R SOD n 7 M mm 4 w, m i., www. ,f l 7 i.. l; w w w m. 7 4 M1 L a 9v wmA A QO; if, N n w w j w w w a 39 1948. B. F. SCHMIDT SUBMERSIBLE DOUBLE-ACTING FLUID PISTON DEEP WELL PUMP 15 sheets-sheet 1o SuventorEE/VJAM/N 5CH/w07;

Filed Aug. 8, 19411 Nw. 3Q, l94. B. F. scHMxDT SUBMERSIBLE DOUBLE-ACTINGFLUID PISTON DEEP WELL PUMP 13 Sheets-Sheet 11 Filed Aug. 8, 1944:inventor NJA/W/MSCHM/orf;

B. F. SCHMIDT SUBMERSIBLE DOUBLE-ACTING FLUID ov. 3Q, R948.

v PISTON DEEP WELL PUMP Filed Aug. 8, 1944 13 Sheets-Sheet 12 nven'torNov. 30, 1948. B. F. SCHMIDT 2,455,922

SUBMERSIBLE DOUBLE-ACTING FLUID PISTON DEEP WELL PUMP 1:5 sheets-sheet13 Filed Aug. 8. 1944 lnventor Patented Nouv. 30, 1948 SUBMERSIBLEDOUBLE-.ACTING FLUID PISTON DEEP WELL PUMP Benjamin F. schmidt. LosAngeles, celu.

Application August 8v, 1944, Serial No. 548,518 15 claims. (ci. 10s-4s)My invention relates to submersible pumps and has particular reference'to an electric motor driven fiuid piston reciprocating insert pump whichis particularly adapted to the pumping of deep wells such as oil wellsand the like.

In the oil producing art it is the common practice to pump oil fromgreat depths by means of reciprocating pumps which are mounted deepwithin the weil bore upon the lower end of la string of flow\ tubingthrough which the puh peti oil is conveyed to the surface and tosuitable storage receptacles. The conventional type of oil Well pumpcomprises a cylinder or barrel within which is moved a reciprocatingpiston or plunger. The plunger is connected to a string of sucker rodswhich extend from the pump through the ilow tubing tothe ground surfacewhere the end of the sucker rod string is connected to a walking beam orpumping jack, by means of which the string of sucker rods isreciprocated to effect a reciprocation of the pump plunger.

This type of pumping apparatus is notoriously ineiiicient and only asmall fraction of the total energy put into the system is useful inraising oil to the ground surface. The principal losses are in thetransmission of power to the pump through the sucker rod stringbecauseof the hysteresis losses attendant upon the alternate elongationand shortening of the sucker rod Astring and friction losses resultingfrom the rubbing of the sucker rod string on the ow tubing. Large lossesare also encountered in the pump itself due to the high friction betweenthe plunger and the barrelcaused by the high pressure against which thepump operates.

The present invention is directed to a pump which will eliminate theenergy losses mentioned above. This is accomplished by employing anelectric motor drive at -the pump location and i transmitting the powerto the pump by means of [an electric cable which is extended down thewell alongside'of the flow tubing. Friction losses 2 It is accordinglyan object of my invention to provide a deep well submersible pump of thecharacter above described which embodies certain novel features ofconstruction permitting the above mentioned designA requirements to bemet.

It is" an additional object of my invention to provide a pump assemblyof the character above described which includes a novel mechanism forpreventing the transfer of uids between parts of the assembly which mustbe kept isolated from each other.

.[t is also an object of my inventionto provide a pump assembly of thecharacter set forth in the preceding paragraphs which is assembled as acompletely self-contained unit including means for attachment to thelower end of a string of flow tubing, allowing the pump to be readilyinserted within a deep well bore.

It is a still further object of my invention to provide a pump assemblyof the character set forth in the preceding paragraphs in which thecomponent parts of the assembly-are removably contained within a singlehousing serving as a carrier for the lcomponent parts of the assemblyand also as a means for supporting the componentlparts in their requiredrelative operating positions.

It is additionally an object of my invention to provide in a pumpassembly of the character set forth hereinbefore a novel sealingarrangement which establishes a seal between the pump assembly and thecarrier when the pump assembly is inserted within the carrier.

It is also an object of my' invention to provide a pump assembly of thecharacter set forth in the preceding paragraphs which includes a meansfor equalizing the pressure exerted by insulating and operating fluidswithin the pump assembly with the static pressure exerted by the columnof fluid extending from the pump to the attached the lower end oi' astring of ilow tubing and showing the 'details of a sealing arrangementused to establish a uid seal between the interior of the pump assemblyand an electric cable used to carry power to the: pump motors;

Fig. 2A is a cross sectional view taken substantially along the lineIIA-IIA of Fig. 2 and illustrating the manner in which the electriccable is secured to the outside oi the flow tubing;

Fig. 3 is a cross sectional view taken substantially along the lineIII-III of Fig. 2 and showing the arrangement of passages for conductingthe pumped fluid to the flow tubing;

Fig. 4 is a longitudinal sectional view of that portion of the assemblywhich lies immediately below the portion illustrated in Fig. 2.

Fig. 5 is a side elevational `view with parts broken away and partsshown in section illustratl cure to each other the component parts showning additional details of construction of the portion shown in Fig. 2; y

Fig. 6 is a longitudinal sectional view illustrating that partl of thepump assembly which lies immediately below the portion shown in Fig. 4;

Fig. 7 is a cross sectional view taken substane tially along the lineVII-VII oi' Fig. 6 and illustrating the manner in which a junction boxsection is secured to the upper end of the rst electric motor assembly;

Fig` 8 is a sectional view taken substantially along the line VIII--VIIIof Fig. 7 showing the manner in which the electric motor lead wires areconnected to the electric cable conductors;

Fig. 9 is a longitudinal sectional view of that part of the assemblylying immediately below the portion shown in Fig. 6;

Fig. 10 is a cross sectional view taken substantially along the lineX--X o Fig. 6 and illustrating additional details of the construction ofthe joint between the motor section and the I,junction 'box section;

Fig. 11 is a longitudinal sectional view of that portion of theassemblywhich lies immediately below the portion shown in Fig. 9;

Fig'. 1 2 is a fragmentary sectional view showing one type of reductiongearing which may be connected to the output shaft of the lower motor;

Fig. 13 is an elevational view of the reduction gearing housing shown insection in Fig. 14;

Fig.` 14 is a longitudinal sectional view oi that portion ofthe-assembly which is disposedim- Fig. 32 is a cross sectional viewtaken substang portion of the assembly which is disposed immediatelybelow the portion shown in Fig. 17, the portion shown in Fig.21 constituting the lowermost portion of the pump assembly;

Fig. 22 is a cross sectional view taken substantially along the lineXXII-XXIIof Fig. 17 and showing the arrangement of the various uid portsand valves operating as the working valves of the pump;

Fig. 23 is a fragmentary longitudinal section of the portion of theassembly shown in Fig. 2l, Fig.- 23 being a section along a plane atright angles to the plane of the section of Fig. 21;

Fig. 24 is a fragmentary longitudinal section taken substantially alongthe plane XXIV- XXIV of Fig. 22 showing the manner in which the valveassembly is secured between the rotary pump unit and the reciprocatingpump unit shown in Fig. 21;

Fig. 25 is a fragmentary sectional view of that portion of the structureshown in the lower portion of Fig. 17, Fig. 25 being taken along a planeat right angles to the plane of Fig. 17;

Fig. 26 is a cross sectional view taken substantially along the lineXXVI--XXVIof Fig. 25 and showing the relative arrangement of the workingvalves and the pump cylinders;

Fig. 27 is a longtitudinal sectional view taken substantially along theline XXVII-XXVII of Fig. 26 and showing additional details of thevalving and port arrangement;

Fig. 28 is a longitudinal sectional view showing a modified form ofprimary pump which may be substituted for the rotary pump shown in Figs.14 and 17;

Fig. 29 is a. cross sectional view taken substantiallyI along the lineXXIX-XXIX of Fig. 28 and illustrating details `of the pump drivingmechanism; I

Fig. 30 is a cross sectional view taken substantially along the lineXXX-XH of Fig. 28 and showing the relative arrangement of the part ofthe pump;

mediately below the portion shown in"Fig.;11

Fig. l5 is a cross sectional view taken substantially along thelineXV-XV of Fig. 14 showing additional details of construction of thereduction gearing;

Fig. 16 is a cross sectional view taken substantially along the lineXVI- XVI of Fig. 14 showing the relative positions occupied by therotating members of a rotary pump;

Fig. 17 is a longitudinal sectional view of that portion oi the assemblywhich is disposed immediately below the portion shown in Fig. 14;

Fig. 18 is a bottom view of the lower end of the pump which is shown inthe upper portion of Fig. 17;

Fig. 19 is a top view of a seat member which' receives the pump assemblyshown at the top of Fig. 17;

Fig. 20 is a cross sectional view taken substantially along the lineXX-XX of Fig. 17 show'- ing the form of attachment means used to seand'showing a reduction gearing arrangement ,whiciifmay be used as analternative to the arrangement shown in Fig. 12;

Fig. 31 is a cross sectional view taken substantially along the lineXXXI-XXXI of Fig. 28 showing the port arrangement employed at the lowerend of the pump shown in Fig. 28;

,tially along the une XXXII-XXXII of Fig. vaff 'aridgshowing therelative positions occupie` bi the check valves shown in Fig. 28; i

' Fig. 33 is a fragmentary longitudinal sectionalv r view similar toFig. 28 but showing another modi'- cation of the invention which isparticularly adapted for lower pressure operation;

Fig. 34 is a sectional viewsimilar to Fig. 33 but showing a diierentmodied form of the invention employing a spring return and springsupporting mechanism for the operating member of the pump;

Fig. 35 is a longtiudinal sectional view showing a modiiled distributingvalve arrangement which may be used in place of the distributing valvear-- rangement; l

Fig. 36 is a cross sectional view taken substanl tially along the lineXXXVI-XXXVI of Fig. 35

and illustrating details of the iiuid port ar rangement;

Fig. 37 is a cross sectional view taken substantially along the lineXXXVII-XXXVII of Fig. 35 showing the relative locations of the fluidpassages and the operating valves;

being contained Within a carrier I which is connected as by means of.acoupling unit 2 (Fig. 2)

to a Wishbone member 3 which is provided at its upper end with anintegrally formed female coupling element 4a adapted to be threadedlysecured to the lower end of a string of flow tubi"-y ing 4.

The coupling member 2 is an annular member which is attached to theupper end of the carrier I as by means of screw threads 5, a gasket 6being interposed between a flanged out portion l of the member 2 and theupper end of the carrier to establish a fluid seal. The coupling member2 is secured to the Wishbone member 3 as by means of studs 8 (Fig. 5)screw threaded into the member 2 and extending upwardly through a .baseportion 9 of the Wishbone member 3 to receive nuts IIJ on their upperends.

The Wishbone member 3 is Y-shaped as shown in Figs. l and and is coredout to provide interior passages II positioned to register with andcommunicate with similarly located passages I2 formed in the couplingmember 2 to provide a fluid communication between the interior of thecarrier I and the interiorA of the flow tubing 4. The Y-shaped Wishbonemember 3 is employed Y, to permit an electric cable I3 to be extendedfrom the exterior of the flow tubing 4 to within the interior of thecarrier I withoutlinterfering with the fluid passage provided betweenthe interior of the carrier I and the interior of the flow tubing 4.

As is shown in Figs. 2, 2A and 5, the electric cable I3 is preferably ofthe steel-clad armored type supported for the full length of the tubing4 by means of figure eight clamps I4 shown in Figs. 2A and 5. This clampmay comprise a metal band I5 which is passed around the flow tubing 4 inone direction and between'the flow tubing and the cable I3` It thenencircles the cable I3 in the opposite direction and completes theencirclement of the flow tubing 4 in the rstnamed direction. Thecross-over between the cable I3 and the tubing 4 is effected -byextending the return portion i6 through a suitable aperture I1 providedin the ilrst portion I8 (see Fig. 5). The ends of the band I5 turnoutwardly to form ears I9 which may be d rawn toward each other as bymeans of a nut and screw 20 to securely clamp the cable I3 to the tubingstring 4.

The coupling member 2 supports a packing assembly for effecting a fluidseal between the coupling member 2 and the cable I3. This packingassembly may comprise an inner metal sleeve 2| which is adhesivelysecured to the inner rubber insulation 22 of the cable I3 as, forexample, by vulcanizing, the metal protecting armor 24 of th'ecable I3being terminated at a point above the sleeve 2|. The sleeve 2| includesan outer cylindrical portion 25 which is received within a bore 26formed in the center of the coupling member 2. The lower end of thesleeve 2| is threaded as shown at 21 to receive a stop nut 23 adapted tobear against the under surface 29 of the coupling member 2.

The cylindrical portion 25 ispreferably grooved as at 30 ,to receive arubber packing ring 3l. That portion of the sleeve 2| positioned abovethe coupling member 2 is externally threaded as shown at 32 to receive alock nut 33 which enters a recess 34 formed in the upper surface of thecoupling member 2, thelock nut 33 serving to clamp the coupling member 2between the lock nut 33 and the stop nut 28. The exterior upper portionof the sleeve 2| is externally threaded as indicated"at 35 to receive apacking gland 35 which' is flanged inwardly at its upper end as at 31 tobear against an upper metal ring 38. Suitable packing material 39 isinterposed between' the ring -38 and the upper end of the sleeve 2|. Amechanical attachment to the cable armor 24 is preferably effected bymeans of an upwardly extending tubular portion 40 formed on the member38 and turned inwardly to engage the spiral recesses characterizing thearmor 24.

This structure, it will be seen, establishes a fluid seal around thecable I3 between the interior of the housing I and the exterior thereof.The

Wishbone arrangement permits the cable I3 to means of an inner housing4I (Fig. 4).

pass from the interior of the carrier I to the exterior ofthe flowtubing 4 while permitting the passages II and I2 to fiuidly interconnectthe flow tubing with the carrier l. These passages serve to conduct thepumped iluid from the pumping mechanism to be described hereinafter tothe ilow tubing and thence to the ground surface.

Since the electrical apparatus to be described hereinafter to which thecable I3 is connected must be adequately insulated and protected fromthe corrosive effects of sulphur, water and acids contained within thepumped fluid, this electrical apparatus is isolated from the pumpedfluid by The housing 4I is mounted concentrically Within the carrier Iand spaced therefrom to dei-lne an annular space Ia forming acontinuation of the fluid passage to the flow tubing 4. As shown in Fig.4, the inner housing 4| comprises a section of thin wall tubing which isthreadedly connectedyThe lower end of the inner housing 4I is connectedas by means of threads 48 to a junction box member 49 (Fig. 6) withinwhich is sup'- ported a suitable termina1 box 50 including connectionstuds 5I (Fig. 8) or an equivalent arrangement for effecting anelectrical connection between conductors 52 contained within the cableI3 and lead wires 53 of an electric motor to be described hereinafter.

The space within the inner housing 4I is normally lled with aninsulating oil. such asy a transformer oil. It is desired to reduce to aminimum the possibility of contamination of the insulating oil containedwithin the inner housing 4I resulting from uid leakage through thethreads 48 or around the packing 4l. I accordingly employ a novelpressure equalizing mechanism for producing within the insulating oilcontained in the inner housing 4I a pressure equal to that exerted bythe duid contained within the carrier I and within the annular space Ia.This mechanism includes a supporting ring 54 which is connected as bymeans of threads 55 the ring 54.

To the outer periphery of the upstanding portion 6I there is suitablysecured as by brazing or soldering an outer pressure expansible elementor bellows 62. An inner like element 63 is similarly secured to theinner surface of the flange 6I. The space between the bellows 62 and 63communicates with the aforementioned passages 60. The upper ends of thebellows 62 and 63 are mutually secured to an annular ring or Washer 64(Fig. 4) mounted within th'e inner housing 4I and loosely receivedtherein so as to be axially movable in response to expansion andcontraction of the bellows 62 and 63 The passages 59, 51, 58 and 68apply to the space between the bellows 62 and 63 a fluid pressure equalto that existing within .the annular space Ia, such pressure comprisingthe -pressure exerted by the column of pumped nuid which extends to theground surface. This pressure tends to expand the bellows 62 and 63 andso tends to displace the insulating oil contained within the innerhousing 4I. This process proceeds only -to the point where the pressureopposing expansion of the' bellows 62 and 63 exerted by the insulatingoil balances the pressure exerted between the bellows by the fluid inthe annular space Ia.

This mechanism thus serves to maintain within Kthe inner housing 4I a-pressure which is .precisely equal to the pressure exerted in theannular space la. There is thus no pressure differential available tocause fluid from the annular space Ia to ,enter the interior of theinner housing 4I and contamination of the insulating oil is thusprevented.

The lower end of the junction member 49 is made with a reduced diameterportion 65 (Fig. 6) -terminating in a ange 66 to permit attachment bolts61 to be employed to secure to the junction member 49 anupper end bellmember 68 of an electric motor indicated generally by the referencecharacter 69. As is shown inFigs.

7 and 8, the reduced diameter -portion 65 ofthe yjunction member 49 isprovided with a plurality of longitudinally extending ribs 1I) which arebored as indicated at 1I to receive the aforementioned motor lead wires53. Between the flange 66 and the end bell member 68 there is placed analignment ring 12 which serves to axially align the end bell 68 with thejunction member 49 and which serves also to prevent rotation of themotor 69 within the carrier I. To this end the member 12 is formed of adiameter substantially equal to the diameter of the flange 66 butincludes radially extending lugs 13 (Fig. 10) adapted to bear againstthe inner surface of the carrier I and engage longitudinal splines 14secured to the interior of the carrier I as by means of plug welds 16. i

'to rotate within a stator 18 contained within a motor housing 19 andsecured thereto as by means of a lock ring 80 threaded into the upperend of the housing 19.

The lock ring is secured as by means oi bolts 8| to the aforementionedend bell member 68 which is counterbored as at 82 to receive the outerrace of a ball bearing 83 by means of which the shaft 11 is supportedfor rotation. A spacer ring 84 may be placed between the outer race ofthe bearing 83 and the aforementioned aligning ring 12 to hold the ballbearing 83`agalnst axial movement. The diameter of the motor housing 19is preferably made somewhat smaller than 4the interior diameterof thecarrier I to define between the housing 19 and the carrier I an annularspace Ib constituting a continuation of the annular space lahereinbefcre mentioned.

The aforementioned bores 1I which receive the motor lead wires 53 areextended through the aligning ring 12 and the end bell member 68 to forma continuous channel through which the lead wires may be extended fromthe motor windings shown in outline at 85. The lower end ofthe motorhousing 19 supports a lower end bell 86 (Fig. 9) which is identical tothe end bell 68 previously described. The bell end 86 supports a lowerball 4bearing 81 which journals the lower end of the motor shaft 11.

It is many times advisable to use a plurality of motors 69 and I have,therefore, shown in Fig. 9 the manner in which a second motor 69' may besecured to and drivably connected to the upper motor 69. The motor endbell 86 cf the motor 69 is connected to the upper end bell 68 of themotor 68, it being understood that the motor 69' is identical in allrespects with the motor 69. An alignment ring 12' identical to thealignment ring 12 previously described is interposed between the endbells 86 and 6B' and the attachment of these end bells to each other iseffected by means of a plurality of bolts 61'.

The shaft 11 of the motor 69 and the shaft 11 of the motor 69 arecoaxially bored at their adjacent ends as shown at 88 and 89 to receivean aligning dowel pin 90. For convenience in assembly, the dowel pin 99isV preferably more or less permanently secured to one of the shafts asby being pressed into the counterbore in that shaft and removablyassociated with the other shaft as by a sliding t between the pin andthe bore in such other shaft.

The lower end of the shaft 11 and the upper end of the shaft 11' arepreferably.machined t0 a hexagonal crcss section or splined to permit asimilarly contoured coupling member 9| -to effect a drivinginterconnection between the two shafts. The length of the coupling 9| ispreferably so selected as to bear against the inner' races of the ballbearings 81 and 83 and hold those inner races in their proper locationin the same manner as the spacing sleeve 84 previously described. Thelower end of the lowermost motor identified generally by the referencecharacter 69 includes a lower end bell 86" which is secured as by meansof bolts 61" to a lower supporting ring 92, a lower aligning ring 12being interposed between the end bell 68' and the supporting ring 92.

' the lower end o f the lowermostmotor shaft 11" by means of a couplingassembly 9| identical with the coupling 9| previously described; Thesupporting ring 92 is also threadedly attached as by means of threads 95to a supporting sleeve 96 which is mounted concentrically within thecarrier I and spaced therefrom to define an annular space I'c comprisinga continuation of the annularspaces Ia and Ib.

The lower end of the supporting sleeve 96 is secured to a coupling andsealing member 91 (Fig. 11) serving as a closure for the lower endof thespace within the sleeve 96. This space, it will be appreciated, isfilled with the insulating oil which fills likewise all of the spaceswithin the motors 69-69" and the junction member 49. Since the shaft 94extends through the member 91, a-uid seal must'be effected between theshaft and the member 91. Accordingly, the member 91 is bored.. a

as indicated at 98 to receive a plurality of springpressed packingelements 99 oi conventional construction. An auxiliary seal or wipercomprising an annular ring of leather or synthetic rubber. may besecured as indicated in Fig. 11 to the upper surface of the member 91.

The lower end of the shaft 94 is also journaled ln the member 91 as bymeans of a ball bearing I0| mounted within a suitable counterbore |02and held in position as by means of a snap ring |03. The shaft 94 isdrivably connected as by means of a splined connection |04 to a shaftextension |05 mounted within an inner housing |06 secured as by means ofthreads |01 to the lower end of the coupling member 91.

As shown in Fig. 14, the inner housing |06 is mounted concentricallywithin the carrier and spaced therefrom to deiine an annular passage Idforming a continuation of the annular passages Ia-Ic. The housing |06 isconnected as by means of threads |08 to a supporting member |09. Thesupporting member |09 is similar to the upper end of the member 49 shownin Fig. 6 and mounts a ring member IIO to which is securedconcentrically disposed bellows and II2. The bellows II and ||2 aresecured at their upper ends to a washer I I3 (Fig. 11) mounted withinthe inner housing 06. A fluid passage arrangement identical to that usedin connection with the bellows 62 and 63 of Fig. 6 is employed to applyto the space between the bellows and ||2 the i same fluid pressure asexists within the passage The space within the inner housing |06 isintended to be filled with a iluid lubricant and the bellows II I and||2 operate in a manner identical to that described in connection withthe bellows 62 and 63 to maintain within the lubricant i'llling thehousing |06 the same pressure as exists within the annular space I d.

The coupling member |09 includes a downwardly depending flange portionI| 4 which is internally threaded to receive an upwardly extendingiiange portion ||5 of the reduction gear housing I6. The reductiongearing which is contained 'within the housing |I6 is indicatedgenerally tby the reference character I I1 and comprises the subjectmatter of my copending application Serial No. 543,517, filed August 8,1944, and entitled Reduction gearing. Briefly stated, it includes acentral *shaft ||8 connected as by a splined coupling I I9 to the lowerend pf the shaft extension 06 and having formed thereon a worm I 20. Theshaft||8 is journaled as by means of bearings 2| and |22. The worm |20meshes with a pair of worm gears |23 (Fig. 15) mounted upon cross shafts|24 suitably supportedv within a carrier |26, the carrier |25 in turnbeing journaled as by means of beatings |26 and |21 within the gearhousing I I6.

Special spiral gears |29 are formed integrally with the worm gears |23and mesh with gear teeth |29 formed on the interior of the gear housingI| 6. The actin of the mechanism is such splined connection |33 to theupper portion of a coupling member |34 which is secured at its lower'end as by means of splines |35 to an upper closure member |36threadedly connected as at |31 to the upper end of a pump housing |38.

The-pump shaft is journaled for rotation relative to the pump housing|38 as by means of a supporting member |39 which mountsbail or othersuitable anti-friction bearings |40 and |4|. A fluid seal around theshaft I3| is obtained by means of packing elements |42.

Attention is directed to the mounting of the ball bearing |40 within thespace provided in the supporting member |39 within which the packingelements |42 are placed. This arrangement serves to hold the shaft |3|in a fixed position within the packing |42 and maintains permanent xedalignment between the shaft and the packing. This avoids thediliiculties often encountered with packed joints in which the packingcrowds to one side and forces the shaft out of line, increasing thefriction and causing rapid wear of the packing and rapid wear of theshaft.

Since the pump housing |38 is slowly rotated l*may comprise parts of arotary pump of any suitable design. I have shown, by way ofillustration, a. well known type of rotary pump which includes a powerrotor |46 (Fig. 17) which is formed integrally or suitably secured tothe pump shaft I3 I. 'I'his rotor has formed thereon a plurality ofspiral vanes |41 which mesh with cppositely inclined vanes |48 and |49formed on a pair of idler rotors |50 and |5I disposed on opposite sidesof the power rotor |46 and suitably journaled for rotation. The lowerend of the power rotor |49 is supported for rotation in a backing member|52 suitably secured as by means of bolts |53 to a lower head member |54which may, as indicated, be formed integrally with the pump housing |38.A fluid seal is established between the rotor |46 and the stationarysealing member |62 by any suitable means such as the packing rings shownat 66.

(k/ l l The head member |54 is the lower end of the pump proper andincludes a suction passage |66 communicating with an inlet bore |51formed in the power rotor |46. The bore |61 extends the full length ofthe power rotor |46 and communicates with a transverse passage indicatedby dotted lines |58 in Fig. 14 so that uid drawn in through the passage|684 will be discharged into the interior of the pump |36 at the upperend of the rotorsl |46, |60 and |6l. As the rotors are rotated, thisiiuid is carried downwardly through the chambers in which the rotorsrotate, is collected in an annular space |69 at the lower end of therotors and discharged through a discharge passage |60 formed in thelower head member |64.

According to my invention. the lower head member |64 serves in a dualcapacity acting also sion |62 formed in a stationary valve member |63.

The -valve member |63 is secured as by means of thread'slt to. the lowerend of the stationary housing |43. Byvv'irtue of this threadedinterconnection, the stationary valve member |63 serves as a bottomclosure for the housing |43.

' That portion of the apparatus just described which lies below thecoupling and sealing member 91 and above the stationary valve member |63is lled with a lubricating oil chosen for its lubricating properties toreduce to a minimum the friction losses and wear in the variousbearings, gears and the like included in the stated portion of thedevice. The rotary pump which is driven by the drive shaft |3| isintended to pump what may be termed an operating fluid." This iiuid maybe oil of the same characterfas that used for lubrication or it maycomprise any one of a number of suitable liquids. This oil is containedin the space and passages to be described hereinafter and situated belowthe stationary valve 4member |63.

The stationary valve member |63 includes a pair of diametrically opposedvertically extending passages |65 and |66. As is shown in Fig. 19, thesepassages terminate in` arcuate grooves |61 -and |66 each extendingapproximately one-quarter of a 'circle about the inclined surface |62.They are positioned to register with similarly disposed arcuate channels|69 and |10 (Fig. 18) formed on the under surface of the head member|54. The inlet passage |66 communicates with one of the channels |69 andthe discharge passage |60 communicates with the other channel |10. Thesurfaces 6| and |62 are in abutting relation to each other and serve ase, fluid seal to prevent leakage of fluid from the aforementionedpassages while permitting the head member |54 to be slowly rotated withrespect to the stationary valve member |63.

The head member |54 is preferably guided during its rotation and held inpressure contact with the female cone surface |62 by means of a stubshaft |1| which is secured as by means of threads |12 to the lower endof the head member |54. The shaft |1| extends into a counterbore |13formed Ain the under side of the stationary valve member |63 andreceives a ball thrust bearing |14. A compression spring |16 confined insuitable retainers |16 and |11 is interposed between the thrust bearing|14 and a nut |16 screw threaded onto the lower end of the stub shaft l1I. Rotation of the nut |18 may be used to eiect an 12 adjustment of thedownward force exerted on the shaft |1l by the spring |15.

. In many cases the. force urging the head member |54 onto the conicalseating surface |62 will be unduly large despite any adjustment that maybe made on the spring |15. It is, therefore, desired to balance a partof the weightresting on the surface |62 by hydraulic means and to thisend I have formed vin the under surface of the head member |54 acircular groove |19 which is connectedY by means of a port to the pumpdischarge port |60. A similar circular groove |8| formed in the seatingsurface |62 may be coinmunicated by means of a small passage |82 withthe annular space lying between the pump housing |36 and the stationaryhousing |13. The fluid pressures which are conveyed to the grooves |19and |8| exert an upward force on the head member |54 balancing at leasta part ofthe weight of the structure resting on the head member |54. Itis preferred to adjust the area of the grooves |61, |68, |69, |10, |19and |9| to provide aseparating force due to. fluid pressure whichexceeds the weight resting on the head member |54. The spring |15 andassociated mechanism may then be used to obtain the desired contactpressure between the head member |54 and the stationaryvalve member |63.

The stationary valve member |63 is secured as by means of bolts |83(Figs. 20 and 24) to a valve block |84 (Figs. 1 7 and 24) a distributingmember |85 and a pump housing |86 (Fig. 21). Through the enumeratedmembers, there are formed continuations 66a, |6617 and |65a. |65b of theaforementioned iiuid passages |65 and |66. The passages I 65h and |661;communicate with similar vertically extending bores |81 and |88 formedin the pump housing |86. The bores |81 and |86 are extended nearly tothe bottom of the housing |86 where they are communicated by means ofdiagonally extended passages |89 and |90 (see Figs. 26 and 27) withcorresponding vertica1 bores |9| and |92 spaced circumferentiallybetween the bores |61 and |88.

The passages I9| and |92 have reduced diameter portions at their lowerends which are internally threaded as indicated at |93 and |94 toreceive the threaded lower ends of a pair of tubular stand pipes |95 and|96. The stand pipes are each fitted at their upper end with ballstanding valves |91 and |88 arranged to discharge iiuid from withinthetube's |95 and |96 into the chambers |9I and |92 near the upper endsthereof. The tubes |95 and |96 communicate with a common inlet passage|99 (Figs. 21 and 25) formed in a foot valve member 200 which may besecured to the pump housing |86 in any suitable manner as by means ofscrews or bolts 20|. The foot valve member 200 mounts a seating ring 202upon which is rested a ball foot valve 203. The member 200 is bored asindicated at 204 to communicate with the ring valve seat 202 and isprovided with a reduced diameter external portion 205 which is threadedat its lower end to receive a lock nut 206 used to hold on the tubularportion 205 a series of pump leathers or packing cups 201 and 208. Thesecups are normally received within a bore 209 formed in the lower end ofa lower closure member 2| 0 which is secured as by means of threads 2||to the central lowex` end of the housing I. The upper surface of themember 2|0 is, by preference, tapered as shown at 2|2 to receiv'e asimilarly tapered lower surface 24|3 formed on the foot valve member200, the mating Surfaces 2|2 and 2|3 serving to hold the assembly thereduction gearing ||1.

in a concentrically aligned position with respect to the housing I.

' The aforementioned chambers |9| and- |92 communicate at their upperends as by means of passages 2|4 and 2|5 formed -in the distributingmember |85 with discharge ports 2|6 and 2|1 formed in thev valve block|84 (Fig. 25). The

passages 2|6 and 2 I1 each communicate as shown in Fig. with the annularspace disposed immediately within the outer housing I. This space, itwill be recalled, is continuous the full length of the instrument andcommunicates with the discharge passages Il formed in the upper wishbonemember 3, and it is by this means* communicated with the tubing string4. The passages 2 I 6 and 2I1 are each fitted with ball check valves 2|8and 2|9 serving to supplement the standing valves |91 and |98 previouslydescribed.

The bores |81 and |88 and the bores |9| and |92 each contain a heavyfluid such as mercury. The level of the fluid in one of its possiblepositions is indicated by the wavy lines 220 and 22| in Fig. 21.

The operation of the device may best beV understood by assuming theparts to be in the positions shown in Figs. 17, 21 and 25. With therotary pump in operation, fluid is drawn in through the passage |56 anddischarged through the passage |60. This fluid under pressure flows intothe passage |66, through the mating of the arcuate 4 channels |68 and|10 and flows downwardly through the passages |66a and |66b into thepump chamber |88. Fluid pressure is thus exerted on the surface 220 ofthe mercury column contained in the passage |88 .and so forces themercury through the diagonal passage |90 into the chamber |92, causingthe mercury to rise in the chamber |92 and displace from that chamberany fluid which may be contained therein and resting upon the surface ofthe mercury. This fluid cannot ow downwardly through the stand pipe |96because the standing valve |98 is closed. It therefore flows upwardlypast the check valve 2 I 8, through the passage 2|6 and into the annularspace immediately within the housing I, whence it is conducted upwardlyto the Wishbone 3 and into the tubing string 4.

At the same time the fluid which flows through the suction port |56 intothe rotary pump |41 is withdrawn from the passage |65 and the passages|650. and |65b to produce a materially reduced pressure within the pumpcylinder |81. The

reduction in pressure on the surface 22| of the mercury column containedtherein serves to withdraw mercury through the diagonal passage |89 fromthe bore |9|. Since the top of the bore |9| is closed by the check valve2| 9, the void tending to be produced by the withdrawal of the mercuryis filled by contact oil or pumped uid which flows upwardly through thepassage 204 past the foot valve 203 and into the space |99 from whenceit is conducted upwardly through the stand pipe |95 and past thestanding valve |91.

During the time this operation is taking place, the head member |54which is secured to the pump housing |38 is slowly rotating with respectto the stationary valve member |63 by virtue of The speed of thisrotation is adjusted to interchange the passages |56 and |60 withrespect to the passages |65 and |66 before all of the mercury has beendisplaced from the bores in which it is contained.

Itwill be noted by referring to Figs. 18 and 19 that duringapproximately one-half of a revolution, the uid connections effected bythe valve anemona |54, |63 are as shown vin Fig. 17. After a one-halfrevolution of the valve member |54, the passage |56 ,is communicatedwith the passage |66 and the passage |60 is communicated with thepassage.

|65. The iiow of oil or other Working fluid caused by the operation ofthe rotary pump is thus reversed in the passages and |66 with the resultthat the rise of mercury in the chamber |86 causes contact oil to bedrawn in through the stand pipe |96, while 4displacement of mercury fromthe chamber |81 causes the contact oil previously drawn into the chamber|9| to be vdischarged past the check valve 2|9 and into the annularspace disposed immediately within the housing I have found that it is.possible to maintain a clean surface on the cylinder bores |81-I88,.|9|

' and |92 by silver plating the surface of these bores arrangement whichis employed by preference to prevent inadvertent loss vof the mercurycontained within the pump chambers. This valve comprises a cage 222suitably secured in the lower end of the bore |81, |88 and defining aseat 223 for a ball valve 224. The ball valve 224 is preferably formedof steel or other metal having a "density less than that of the mercuryor fluid used as a fluid piston. The ball valve, therefore, consequentlytends to rise to the surface of the fluid piston. This is prevented bymeans of a cross pin 225 vextended across the cage above the valve in aposition to arrest upward movement of the valve. Should. however, thelevel of the mercury be depressed to the level of the ball 224, the ballwill follow the mercury level down until the ball seats on the seat 223,closing off the passage |90 and preventing further discharge of mercury.

If desired, the single foot valve member 203 may be replaced by a doublevalve arrangement of the character shown in Fig. 23 wherein the passage|99 is divided into two passages 226 and 221' each closed by a separateball valve member 228. 229.

It is desired at this point to direct attention to the fact that theconnection of the above described assembly to the outer housing iseffected at .the upper end by the female member or upper closure 2 andat the lower end by the packingr elements 201 and 208 which are receivedwithin the lower restricted bore 209. With this arrangement, l partingthe screw threaded joint 5 (Fig. 1) allows the entire assembly to bewithdrawn as a unit from the housing I, the cup packing members 201 and208 merely sliding upwardly through the bore 209. Installation ,isaccomplished by a revers'e operation, the`cup form of the packingmembers 201 and 208 permitting that assembly to be readily slippeddownwardly through the bore 209. Making up the threaded connection 5completes the assembly.

I have illustrated in Figs.. 28-34 alternative rotary pump constructionswhich may be employed if desired instead of the rotary pump shown inFigs. 14 and 17. Reference to Fig. 28 will show that in the modificationillustrated therein, the pump shaft 3| is terminated in a. rotating disk230. This disk is provided with a transverse slot 23| within which isVmounted a`

